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comparison src/luan/Lua.java @ 1:2df768b926aa

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start Luan git-svn-id: https://luan-java.googlecode.com/svn/trunk@2 21e917c8-12df-6dd8-5cb6-c86387c605b9
author fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
date Tue, 13 Nov 2012 05:54:32 +0000
parents
children 4da26b11d12a
comparison
equal deleted inserted replaced
0:a89d06646ff3 1:2df768b926aa
1 package luan;
2
3
4 public class Lua {
5
6 public static String toString(Object obj) {
7 if( obj == null )
8 return "nil";
9 return obj.toString();
10 }
11
12 public static String type(Object obj) {
13 if( obj == null )
14 return "nil";
15 if( obj instanceof String )
16 return "string";
17 if( obj instanceof Boolean )
18 return "boolean";
19 if( obj instanceof LuaNumber )
20 return "number";
21 return "userdata";
22 }
23
24 public static int length(Object obj) throws LuaException {
25 if( obj instanceof String ) {
26 String s = (String)obj;
27 return s.length();
28 }
29 if( obj instanceof LuaTable ) {
30 LuaTable t = (LuaTable)obj;
31 return t.length();
32 }
33 throw new LuaException( "attempt to get length of a " + type(obj) + " value" );
34 }
35
36 static LuaNumber toNumber(Object obj) throws LuaException {
37 if( obj instanceof LuaNumber )
38 return (LuaNumber)obj;
39 if( obj instanceof String ) {
40 String s = (String)obj;
41 try {
42 return new LuaNumber( Double.parseDouble(s) );
43 } catch(NumberFormatException e) {}
44 }
45 throw new LuaException( "attempt to perform arithmetic on a " + type(obj) + " value" );
46 }
47
48 static LuaNumber add(Object n1,Object n2) throws LuaException {
49 return new LuaNumber( toNumber(n1).n + toNumber(n2).n );
50 }
51
52 static LuaNumber sub(Object n1,Object n2) throws LuaException {
53 return new LuaNumber( toNumber(n1).n - toNumber(n2).n );
54 }
55
56 }